Hide activities when AOD comes in

Display timeout does not lock the keyguard, which means that
activities won't immediatelly disappear.

We need to factor AOD into to equation to make sure that
the user won't see phantom activities under the status bar
window when the display times out.

Fixes: 73120928
Test: open Settings, wait for display timeout
Test: Wait for display timeout, press power, see launcher
Test: Launch maps, start navigation (FLAG_SHOW_WHEN_LOCKED)
Test: Go to AOD, press power button: activity is occluding keyguard
Test: Press home: bouncer shows up
Test: Unlock: maps goes into pip mode
Test: Go to AOD and back to lock screen: keyguard visible
Test: Expand maps, go to AOD, back to lock screen: maps is occluding keyguard
Change-Id: I9b7512313af2f851d8788ec53de7880bce3bed2c